Ighting circuit system

ABSTRACT

An electrical system for regulating the output potential to a lighting circuit for a vehicle from an existing electrical generating device driven by the engine of the vehicle whereby the potential to the lights will be sufficient to provide adequate lighting over the usable speed range of the engine.

United States Patent 1191 Carmichael et al. Aug. 7, 1973 [54] LIGHTING CIRCUIT SYSTEM 3,092,767 6/1963 Schilling 323/76 [75] inventors: Thomas lf carmichgel, Qrayton Plains; Richard J. Maier,

Pontiac, both of Mich; Primary Examiner-R0y Lake William J. Kirkpatrick, Assistant i? i ill Bryan, Ohio Attorney-J. King Harness, William L. Anthony, Jr. [73] Assignee: Syncro Corporation, Oxf0r d, i\/iicii. etal' [22] Filed: June 28, 1971 [2i] Appi. No.1 157,329 ABSTRACT 52 US. Cl 315/79, 240/7.6, 315/79, An electrical System for regulating the Output Potential 22 73 3 7 to a lighting circuit for a vehicle from an existing elec- {511' 1111. c1 8601; 1/26 meal generating device driven y the engine f the 58 Field of Search 240/7.6, 8.1-, hiele whereby the Potential to the lights will be 1 315/77, 7 9 2; 2 7 79323176, 79 cient to provide adequate lighting over the usable 1 speed range of the engine. [56] lleicrencen Cited UNITED Sir/WES "ATENTS ll Claims. 4 Drawing Figures 2,509,662 5/1950 Wisman 322/78 1 LIGHTING CIRCUIT SYSTEM SUMMARY BACKGROUND OF THE INVENTION The present invention relates to an electrical system for regulating the potential to a vehicle lighting circuit.

Vehicles such as snowmobiles have their lights energized by a generating device such as a magneto which also provides electrical energy for the ignition system of the vehicle engine. The output of the generating device, however, varies with engine speed and where there is no battery in the system, at low engine speeds, such as idle, the lights may dim considerably. This can be especially troublesome if the vehicle is being driven and while it is moving at a fair rate of speed the operator permits the vehicle to coast by releasing the accelerator pedal. In this condition the vehicle may still be moving rapidly but thevehicle operators visibility will be substantially reduced since the lights will dim. Another problem occurs in multiple lighting systems if one light burns out. With some generating devices this reduction in load will result in a substantial increase in potential at high speeds to a magnitude sufficient to overload and burnout the remaining light or lights. In the present invention a simple circuit system is provided which can be readily connected to the existing leads from the generating device and which regulates the output potential such that the potential at the low speed end is boosted to substantially improve the lighting at low engine speeds and the potential is regulated such that at high engine speeds the potential applied to a remaining light or lights will not be excessiveto burn out such light or lights in the event one light does burn out.

Therefore, it is an object of the present invention to provide an electrical system for use with the lighting windings of a generating device whereby the potential to the lights will be regulated.

It is another object to provide an electrical system for use with the lighting winding of a generating device for boosting the potential at low speeds such as idle to improve the lighting at such low speeds.

It is another object to provide an electrical system for use with the lighting winding of a generating device whereby the potential at high speeds will be regulated to prevent burn out of the remaining light or lights in the event one light burns out.

- The present invention utilizes a specially tuned resonant circuit to providethe improved lighting function. Therefore it is another object to provide a resonant system in combination with the lighting windings of a generating device for regulating the ing winding. I 1

a The system of the present invention is also useful where a battery is in the system and is used to regulate the charging potential to the battery such as to provide sufficient potential at low engine speeds and also provides regulation to the lights in the event the battery is removed from the circuit and the vehicle is operated solely via the potential from the generating device; in this event the system of the present invention will provide a regulated potential to the lights boosting the low speed end and preventing burn out at the high speed end.

Therefore it is another object of the present invention to provide an electrical system for use with a lighting circuit including a battery and battery charge circuit whereby a regulated potential is provided for potential of the light charging the battery and, in the event the battery is re; moved, a regulated potential is provided for lighting the lights.

Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawing in which:

FIG. 1 is a schematic diagram of the lighting winding of an electrical generating device and an associated lighting circuit and an electrical circuit embodying features of the present invention;

FIG. 2 is a schematic diagram of a modified form of electrical circuit;

FIG. 3 is a different form of electrical circuit including features of the present invention; and

FIG. 4 is a modified form of system for use with a battery charging circuit and lighting circuit.

Looking now to FIG. 1 a permanent magnet electrical generating device is partially shown and is indicated by the numeral 10. The operating device 10 has a rotor 12 adapted to be driven by the engine of a vehicle such as a snowmobile, and includes a plurality of circumferentially spaced permanent magnets 14 of alternating polarity. The magnets are preferably made of a ceramic material such as barium ferrite. A stator 16 includes a plurality of radially extending, circumferentially spaced poles 18. On two of the poles are wound lighting windings 20 and 22 which are electrically connected in series aiding relationship via a conductor 24 which is grounded via ground 26 whereby the windings 20 and 22 define a grounded center tapped winding. Output conductors 28 and 30 are connected to opposite sides of windings 20 and 22. A pair of lights 32 and 34 are connected in parallel. In a conventional circuit one side of the lights 32, 34 is connected to ground and the other side is connected to one of the conductors 28 or 30 whereby the lights 32, 34 are connected across only one of the windings 20, 22 to ground. With such a lighting circuit, however, the lights 32, 34 will be dimly lit at low speeds such as idle and at high speeds, if one'of the lights 32, 34 is burned out, the other of the lights may be burned out because of the excessive voltage generated. These problems are connected by the cir-v cult of FIG. 1. In FIG. I,- the lights 32, 34 are ungrounded and are connected in parallel to a resonant circuit 36 which is connected to conductors 28 and 3t).

The resonant circuit 36 includes a capacitor 38 connected between conductors 28 and 30 and hence across the windings 20, 22; another capacitor40 is connected between conductor 30 and one side of lights 32, 34. Note that in some existing generating device constructions the center tap lead is difficult to get at and only the leads such as leads 28 and 30 are readily accessible; therefore the circuit of FIG. 1 provides a simple circuit connection for. such generating devices.

An engine driving the rotor 12 will vary in speeds. over the speed range, from around L000 rpm. (at idle) to around l0,000 r.p.m. (at wide open throttle). The voltage output from the generator 10 will vary generally as a straight line with speed. In conventional sys-- at or near idle speeds, will be too low to adequately energize the lights and will be unnecessarily high at maximum speeds resulting in premature light burn out. In this regard it should be noted that the variations in voltage have a substantial effect on light output since for an incandescent lamp the light output in lumens varies generally as the square of the applied voltage.

The capacitor 40 is selected to boost the low speed voltage output while the capacitor 38 tends to regulate or lower the high speed voltage output. The capacitor 40 can be considered to be in series resonance with the windings 20 and 22 and in series with the parallely connected lights 32, 34; the capacitance 38 can also be considered to be in series resonance with the windings 20 and 22 while it is in parallel with lights 32, 34. For an engine having a speed range of from around 1,000 r.p.m. to around 10,000 r.p.m., the'capacitor 40 is selected to have a magnitude where its capacitive reactance equals the inductive reactance of windings 20 and 22 at an engine speed of around 2,000 r.p.m. This point of resonance is selected taking into consideration the resistive impedance of the series circuit as provided mainly by the resistance of the lights 32, 34. The resistance of the circuit will lower the Q of the series resonant circuit and will also result in a generally flat response over a substantially wide speed range. By select.- ing the point of resonance, considering the Q of the circuit asaffected by theresistive impedance, to be proximate to the idle speed of the engine, the voltage output an increase in circulating current flowing from windings 20 and 22 to capacitor 38 which in turn will result in an increase in the back m.m.f.; this will provide a regulating effect by reducing the'voltage generated by windings 20 and 22. Note that the capacitor 38 has a magnitude whereby ithas-little effect over the low speed range but is effective at higher speeds. In one preferred form the magnitude of capacitor 40 was approximately I20 times the magnitude of capacitor 38.

In this same form of circuit where not capacitors 38- and 40 were used the output voltage for one generator was 6.9 voltSatlgZOO r.p .rn.and 15;.5 volts at 7,7S

r.p.in/Whe'n the 'capeci'tors uand 4Q were 'used' the output voltage for the same generator was-l 1.9 volts at 1,200 r.p.m. and 11.6 volts at 7,750 r.p.m.

' The embodiments of FIGS. 2 4 are modifications of the circuit of FIG. l'for use with the generator 10. In

these embodiments only the structure different from that of FIG. I has been shown and similar components a serving similar functions are given the same numerical designation with the addition of a letter postscript.

The embodiment of FIG.. 2 shows a modified form of lighting circuit in which the lights 32a and 34a are connected in parallel and have one end grounded. The lights are normally grounded at one end in existing installations and with the circuit of FIG. 1 the lights 32 and 34fla're ungrounded. In' FIG. 2 capacitor 40a is a part of a series resonant'c ircuit 36a and is connected in series with windings 20 and22 of generator via conductors 28 and 30. The capacitor 40a is connected in series with the primary P of a transformer with the series circuit of capacitorl40a and primary P being connected in series with windingsand 22. A secondary' winding S of transformer T is connected to the ungrounded side of lights 32a and 34a via conductor 42. The magnitude of capacitor 40a is selected to be in res onance with the inductance of transformer T, via primary P, and windings 20 and 22 whereby the voltage output to lights 32a and 34a is boosted at the low end to substantially. improve the lighting at low engine speeds such as engine idle.

The system of FIG. 3 is similar to that of FIG. 1 except that the lights 32b and 34b are maintained with one end at ground. The capacitor 38b provides a parallel resonant circuit with both windings 20 and 22 while capacitor 40b provides a series resonant circuit only with winding 22 (since the lights 32b. and 34b in the series resonant circuit are connected'to ground at one end.) As with the embodiment of FIG. 1 the series'and parallel resonant circuits act to increase the voltage at the low speed end (idle) and regulate or reduce the voltage at the high speed end.

1 FIG. 4 shows another circuit in which the lights can 'be maintained grounded. Thus lights 32c and 34c are connected in parallel and have one side grounded. The opposite side of lights 32 and 340 islconnected to the positive side of a battery B which has its opposite side grounded. Battery B'is charged by d-c current from the alternator 10 via diodes D1 and D2 which, are connected to conductors 28 and 30, respectively. Note that the lights 32c and 34c are energized by battery B aswell as generator 10. The battery B acts as a stabilizing or regulating element relative to the generator l0'andin this regard acts to protect lights 32c and 34c from burn out by preventing the. generated output voltage from becoming excessively high at high engine speeds, However, in the event thebattery is removedfor replacement and the engine is still used then the lights 32c and 34c could not be protected. Capacitor'38c is connected across conductors 28 and 30 and hence isconnected in parallel with the windings 20 and 22. The capacitorc is selected with parameters similar to capacitors 40 and 40b and is in resonance with windings 20 and 22 at lower engine speeds. This will act to boost the voltage applied to battery B for charging at lower engine speeds and since capacitor 40c does parallel the windings 20 and 22 it will, at higher engine speeds, act as a shunt; the shunt current will tend to, shut down the alternator l0 and hence limit the voltage to the lights 32c and 340 f thigherengine. speeds; in" this way, in the event the engine is used with the battery B out of the circuit, the circuit of capacitor 380 will prevent the voltage to the lights 32c and 34c from becoming excessive and burning these lights out. Q

While it will be apparent that the preferrede'mbodia merits of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation' and change without. departing from the proper scope or fair meaning of theinvention. s What is claimed is: i

1. In a lighting circuit fora vehicle having a generator driven by an engine with the speed of theengine vary ing the speed of the generator and hence the output.

voltage of the generator, a regulating circuit comprissirable level, resonant circuit means externally con-. nected to the generating windings of the generator including a first capacitor electrically connected in a se ries circuit with the lights and the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the windings to provide resonance at a preselected low generator speed range for boosting the voltage to the lights over said preselected low generator speed range whereby. adequate illumination will be obtained over substantially the entire speed range of the generator including said preselected low generator speed range, and a second capacitor electrically connected in a parallel circuit with the generator windings and having a magnitude selected relative to the inductance of theremainder of the circuit including the windings for providing resonance at an intermediate generator speed and for providing a recirculating current at generator speeds higher than said intermediate generator speed whereby the voltage from the windings will be reduced at such higher speeds.

2. The circuit of claim 1 for a generator having an operating range of from around 1,000 to around 10,000 r.p.m. and with said first capacitor providing resonance at around 2,000 r.p.m., said second capacitor providing resonance at around 5,000 r.p.m.

3. The circuit of claim 2'with said second capacitor having a magnitude for providing a recirculating current at generator speeds higher than said intermediate engine speed whereby the potential from the windings will be reduced at such higher speeds.

4. The circuit of claim 1 with the windings being center tapped'to' ground and with said conductor means connecting said first capacitor and the lights in an ungrounded circuit across the windings. 5. The circuit of claim 1 with the windings being center tapped to ground and with said resonant circuit means including transformer means for coupling to the lights, said conductor means connecting said first capacitor in an ungrounded circuit to said transformer means and across the windings and connecting the lights to said transformer means in -a grounded circuit.

6. The circuit of claim 1 with the windings being center tapped and with said conductormeans connecting the lights to said resonant circuit means in a grounded circuit.

7. The circuit of claim 1 with the windings being center tapped to ground, said resonance circuit means including a transformer having primary and secondary windings, said conductor means connecting said first capacitor in series with said primary and across the windings in an ungrounded circuit, said conductor means connecting said secondary to the lights in a grounded circuit.

8. The circuit of claim 1 with the windings being center tapped to ground, said conductor means connecting said second capacitor across the windings in an ungrounded circuit, said circuit means connecting said first capacitor to the lights in a grounded circuit.

9. The circuitof claim 1 with the windings being center tapped to ground, said conductor means connecting said first capacitor across the windings in an ungrounded circuit, said conductor means comprising a pair of diodes connected to opposite sides of said first capacitor, said conductor means connecting said diodes to the lights and connecting the lights to ground, a battery, said conductor means connecting said battery across the lights. I

10. The circuit of claim 1 with said first capacitor havinga magnitude'relative to the inductance of the remainder of the circuit and the resistance of the circuit including the resistance of the lights to define a resonant circuit having a relatively low 0 whereby the voltage over said preselected low speed range will be generally uniform.

l 1. For a generator in which the output voltage of the generator varies with the speed of the generator, 21 regulating circuit comprising: resonant circuit means externally connected to the generating windings of the generator includinga first capacitor electrically connected in a series circuit with the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the generator windings for boosting the output voltage of the r generator at a predetermined low generator speed, and

a second capacitor electrically connected in a parallel circuit with the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the generator windings for reducing the output voltage of the generator at generator speeds higher than said low generator speed whereby the output voltage of said generator is controlled'over an extended generator speed range.

k k t 

1. In a lighting circuit for a vehicle having a generator driven by an engine with the speed of the engine varying the speed of the generator and hence the output voltage of the generator, a regulating circuit comprising: conductor means electrically connecting lights of the vehicle to generating windings of the generator with the generator windings normally providing a low voltage to the lights over a low generator speed range whereby the illumination from the lights is not at a desirable level, resonant circuit means externally connected to the generating windings of the generator including a first capacitor electrically connected in a series circuit with the lights and the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the windings to provide resonance at a preselected low generator speed range for boosting the voltage to the lights over said preselected low generator speed range whereby adequate illumination will be obtained over substantially the entire speed range of the generator including said preselected low generator speed range, and a second capacitor electrically connected iN a parallel circuit with the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the windings for providing resonance at an intermediate generator speed and for providing a recirculating current at generator speeds higher than said intermediate generator speed whereby the voltage from the windings will be reduced at such higher speeds.
 2. The circuit of claim 1 for a generator having an operating range of from around 1,000 to around 10,000 r.p.m. and with said first capacitor providing resonance at around 2,000 r.p.m., said second capacitor providing resonance at around 5,000 r.p.m.
 3. The circuit of claim 2 with said second capacitor having a magnitude for providing a recirculating current at generator speeds higher than said intermediate engine speed whereby the potential from the windings will be reduced at such higher speeds.
 4. The circuit of claim 1 with the windings being center tapped to ground and with said conductor means connecting said first capacitor and the lights in an ungrounded circuit across the windings.
 5. The circuit of claim 1 with the windings being center tapped to ground and with said resonant circuit means including transformer means for coupling to the lights, said conductor means connecting said first capacitor in an ungrounded circuit to said transformer means and across the windings and connecting the lights to said transformer means in a grounded circuit.
 6. The circuit of claim 1 with the windings being center tapped and with said conductor means connecting the lights to said resonant circuit means in a grounded circuit.
 7. The circuit of claim 1 with the windings being center tapped to ground, said resonance circuit means including a transformer having primary and secondary windings, said conductor means connecting said first capacitor in series with said primary and across the windings in an ungrounded circuit, said conductor means connecting said secondary to the lights in a grounded circuit.
 8. The circuit of claim 1 with the windings being center tapped to ground, said conductor means connecting said second capacitor across the windings in an ungrounded circuit, said circuit means connecting said first capacitor to the lights in a grounded circuit.
 9. The circuit of claim 1 with the windings being center tapped to ground, said conductor means connecting said first capacitor across the windings in an ungrounded circuit, said conductor means comprising a pair of diodes connected to opposite sides of said first capacitor, said conductor means connecting said diodes to the lights and connecting the lights to ground, a battery, said conductor means connecting said battery across the lights.
 10. The circuit of claim 1 with said first capacitor having a magnitude relative to the inductance of the remainder of the circuit and the resistance of the circuit including the resistance of the lights to define a resonant circuit having a relatively low Q whereby the voltage over said preselected low speed range will be generally uniform.
 11. For a generator in which the output voltage of the generator varies with the speed of the generator, a regulating circuit comprising: resonant circuit means externally connected to the generating windings of the generator including a first capacitor electrically connected in a series circuit with the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the generator windings for boosting the output voltage of the generator at a predetermined low generator speed, and a second capacitor electrically connected in a parallel circuit with the generator windings and having a magnitude selected relative to the inductance of the remainder of the circuit including the generator windings for reducing the output voltage of the generator at generator speeds higher than said low generator speed whereby the output voltage of said generator Is controlled over an extended generator speed range. 